possible engine swap?!?!

[Guest]

Ok sooo this is my first post on here and its a question ive been pondering. .. i have a 79 gs850g and access to a 1100g 2v engine only. .. could i install said engine in my 850 frame???
Also could someone point out how to post pictures? Lol

[azr]

How to post pictures

http://members.dslextreme.com/users/bikecliff/images/how_to_post_pictures.pdf

Not sure about the 1100G into the 79' frame, it could probably be made to fit with a few minor mount changes, I'm sure someone else will chime in on it that knows more than I. Welcome to the site.

[Steve]

Installing the 1100 into your '79 will at least require the engine mounts from the 1100, carbs, airbox, ignition system (ignitor) and driveshaft. There will be some re-wiring necessary for the ignitor, but nothing too major.

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[brandonbeezy]

Ok so i think i attached a picture lol. Thanks for the welcome and quick replies! If the pic is attached its a before and current of it.. the previous owner painted it like a Christmas trees then set it on fire... LOL so im going through it replacing the harness next week and last week bought a set of coils from my buddy off his gs1000

[brandonbeezy]

PicsArt_1417555949932.jpg ok i think this is it,

[brandonbeezy]

Yay!!!!!!!!! !!!! I got it!!!!! Hahaha

[brandonbeezy]

The major issue i was thinking about last night was drive shaft placement (side to side) but now that im more awake I think if that were an issue i could slide the motor over

[Steve]

Yay!!!!!!!!! !!!! I got it!!!!! Hahaha

You are almost there, they are still thumbnails.

Here:




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[Brendan W]

Installing the 1100 into your '79 will at least require the engine mounts from the 1100, carbs, airbox, ignition system (ignitor) and driveshaft. There will be some re-wiring necessary for the ignitor, but nothing too major.

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Might it be easier to swap the 850 chassis into the 1100

[azr]

The major issue i was thinking about last night was drive shaft placement (side to side) but now that im more awake I think if that were an issue i could slide the motor over

Pretty sure that lines right up from what other people have said. So you don't have access to the final drive of the 1100G? too bad, lots of people will use those on their 850's or 1000's as they have a better gearing for the highways. Not by much, only drops top rev's down by 300rpm or so but it all helps. Good luck with the project, looks like you'll have to start making a 'parts needed' list.

[Steve]

Might it be easier to swap the 850 chassis into the 1100

Not quite sure I am following your logic, but there are too many detail differences in the frames if you try to change the bodywork. Just changing out the engine mounts and other bits mentioned is not all that hard.

By the way, the swingarm can remain the same, only the driveshaft inside it needs to be changed. The flange on the output of the secondary drive is larger on the 1000 and 1100, you need the larger flange on the proper shaft to match up to it.

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[brandonbeezy]

Im not worried about the gearing, not gonna be on the highway very much at all. Will the bike be able to handle the extra power?? Whats the power and weight of the 1100 compared to the 850. Im basically just looking for more "easy" power and there seems to be more aftermarket available for the 1100 but also the 850 frame seems a little smaller? So could be lighter and that 850 badge would throw people way off lol

[Jedz123]

I know when I did My 7/11 swap on my 750, frame flex was a definite issue. Wheelied like crazy... However we are talking about 2 totally different beasts here. The 1100 16V "CHAIN DRIVE" engine was actually designed to produce more high-end street/strip performance power where as the shaft drive 8V G motors were more meant for highway, long term, low end power delivery. I think the 850 frame is more like an 1100 frame then a 750 frame so you should be set rigidity wise. The 850 has 37mm Fork tubes which is common to the big block GS's where as my 750 only had 35mm tubes. I'd say you look pretty set. I have yet to drive a shafty GS though... Maybe some other folks can put their 2 cents in... What would be a real hoot is if you put an 1100G engine in a 650G frame.... I know, I know... It won't work.
My 2 pennies.

[Brendan W]

Not quite sure I am following your logic, but there are too many detail differences in the frames if you try to change the bodywork. Just changing out the engine mounts and other bits mentioned is not all that hard.

By the way, the swingarm can remain the same, only the driveshaft inside it needs to be changed. The flange on the output of the secondary drive is larger on the 1000 and 1100, you need the larger flange on the proper shaft to match up to it.


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I was just wondering at what point does an 1100 engine and transmission transplant to an 850 effectively become an 850 frame and chassis transplant to the 1100.
Some folks might find the second option easier

[Steve]

I was just wondering at what point does an 1100 engine and transmission transplant to an 850 effectively become an 850 frame and chassis transplant to the 1100.
Some folks might find the second option easier

The problem there is that the tank, seat, tail piece and side covers all mount to or hang from the frame. In this case, they simply don't match up.

Changing just the engine really makes more sense.

The only things complicating the matter:
- engine mounts are different, the 1100's mounts should bolt to the 850 frame.
- the carbs on the 1100 are different (larger), which requires the use of the 1100's airbox. It will hang from the same mounts in the frame.
- the 'choke' is different on the 1100. Easy enough to graft the left handlebar control housing to the 850. (I have done it.)
- his 850 has points, the 1100 has electronic ignition, hence the ignitor and its wiring.
- the output flange on the 1100 is larger, so it needs the driveshaft that matches it. The other end (at the final drive) is the same.

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